AB0315 ESTABLISHED RHEUMATOID ARTHRITIS PATIENTS APPEAR TO HAVE IMPAIRED QUADRICEPS MUSCLE MORPHOLOGY ASSESSED BY ULTRASOUND AND MUSCLE STRENGTH IMPAIRED OVER TIME: A COHORT STUDY
Authors: L. Santos, R. Cavalheiro Do Espírito Santo, E. Pena, L. Denardi Dória, A. L. Mallmann, S. Pilotti, D. Moraes, M. Antunes, V. Hax, C. Brenol, O. Monticielo, R. Chakr, R. Xavier
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Rheumatoid arthritis (RA) patients usually present extra-articular manifestations [1], which affect muscle strength, muscle mass and physical functional [2]. There are several methods to assess muscle mass and, among these methods, muscle ultrasound (MU) has been suggested as an alternative to assess muscle morphology [3]. <h3>Objectives</h3> [1] To assess the MU of the quadriceps muscle and verify changes over time (1-year) in muscle thickness and pennation angle in RA patients; and [2] to verify the of changes in clinical features, muscle strength, physical functional in over time in RA patients. <h3>Methods</h3> RA patients, age ≥18years and who met 2010 American College of Rheumatology criteria were included. Morphological parameters in quadriceps muscle consisted of the muscle thickness and pennation angle of rectus femoris (RF), vastus intermedius (VI) and vastus lateralis (VL). RA activity was measured by 28-joint disease activity score (DAS28) assessed by C-reactive protein (CRP), muscle strength by handgrip, and physical functional by health assessment questionnaire (HAQ) and timed-up-and-go (TUG) test. The paired samples Wilcoxon test was used to compare variables between the baseline and 1-year assessments. The significance level was set at p≤0.05 for all analyzes. <h3>Results</h3> At baseline, 155 patients with median of age 60.00 (52.00-65.00) years old, disease duration 11.00 (6.00-20.00) years and DAS28-CRP 2.77 (2.02-3.76) were included. Until moment, twenty-two patients completed the 1-year follow-up. Among these re-evaluated patients, there was a decrease in the VL (-11%) and VI (-13%) pennation angles of quadriceps muscle, and decrease in muscle strength assessed by handgrip test (-36%) after 1-year. On the other hand, no changes were observed in muscle thickness, RF pennation angle, DAS28-CRP, HAQ, and TUG test in over time (p&gt;0.05; table 1). <h3>Conclusion</h3> These preliminary observations indicate that established RA patients have impaired muscle quality (pennation angles) and impaired muscle strength over time. However, it is necessary to complete the remainder of the reassessments to confirm these findings, besides verifying the associations with clinical parameters. <h3>References</h3> [1] Summers GD, et al. Rheumatology (Oxford). 2008;(4) 1124–31. [2] Dos Santos LP, et al. Diagnostics (Basel). 2021 29;11(11):2014. [3] Cruz-Jentoft AJ, et al. Age Ageing. 2019;48:16–31. <h3>Acknowledgements</h3> We thank the Foundation for Research Support of the Rio Grande do Sul State (Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul-FAPERGS), the Coordination for the Improvement of Higher Level Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—CAPES) institution, the Research and Events Incentive Fund (Fundo de Incentivo à Pesquisa e Eventos-FIPE) of HCPA and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico—CNPq). <h3>Disclosure of Interests</h3> None Declared.